Transcoding while recording

Have you considered an option to Transcode while recording? My reason for asking is PLEX has an option for “CONVERT VIDEO WHILE RECORDING” but I do not think it works well. And also PLEX does not seem to use Hardware Transcoding. I can point PLEX to Channels DVR folder and I think it works but then it is doing software transcoding which drains the CPU. I currently record GOLF on the weekends and the size of the recordings are huge. Not a high priority but thought I would ask.

While possible, this also has the ability to bring your system to a terrible halt. With the way we support tuners, we practically encourage tons of tuners so you can record as many things at once and never have a conflict. That creates the possible scenarios of 3-4 transcodes happening at once. There’s not a lot of systems that could handle that kind of mpeg2 transcoding load.

I think the better option is to have an optimization feature that transcodes after a recording takes place. That way Channels DVR can schedule the transcoding times and have more control over it to manage how many happen at once and so they happen during off peak times.

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Good idea. Thanks of the detailed response.

I think the better option is to have an optimization feature that transcodes after a recording takes place. That way Channels DVR can schedule the transcoding times and have more control over it to manage how many happen at once and so they happen during off peak times.

This would be another killer option (and selling point) for Channels DVR. Post-processing a file (transcoding, moving) the way you already do with Comskip would be just awesome. Maybe you can even use Comskip info for add-free transcoding…

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Totally agree with you. Plex would bring my QNAP TS-670 Pro quad Core to 45% CPU utilization when watch Live TV or record. Channel DVR always keeps it below 5% CPU utilization. Please keep it as is. That’s why I abandon Plex completely because of constant CPU utilization. If you want to make this feature available, please keep it optional with warning about CPU, please don’t make this as default.

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This could always be an option that was enabled or disabled so as to not bring peoples systems to their knees. Could also put a max number of active transcodings. I’ve tested this feature on emby and it works pretty good for live transcoding of recordings. The cpu isn’t too bad, its basically the equivalent of watching 2 shows if that was what I was doing. The actual cpu load is limited by how fast it receives data. It can only record in real time.

setup an hls stream for the recording and then attach a recording process to that stream. then allow people to watch said hls stream as well. this is how emby handles it and it seems to work ok for my little nas.

If I take an SD recording and transcode it to h264 crf 17 with no bitrate options the file goes from 468mb to 252mb. Below is command line. There is no quality loss that I can tell in this one.

“/volume1/@appstore/ChannelsDVR/channels-dvr/latest/ffmpeg_real” -hide_banner -i ./That\ '70s\ Show\ S07E06\ 2004-11-03\ Rip\ This\ Joint\ 2017-08-04-1430.mpg -preset veryfast -crf 17 -profile:v high -level 4.1 -x264opts:0 subme=0:me_range=4:rc_lookahead=10:me=dia:no_chroma_me:8x8dct=0:partitions=none -g 60 -vf yadif,crop=in_w:in_h-120 -c:a aac -ac 2 test.mp4

I really like the idea of scheduled transcoding and also multiple options. However, part of the reason I brought it up is because I believe live tv transcoding is an option already with the remote access and web viewing. The big difference between PLEX and Channels is that 1) Channels support Hardware Transcoding and PLEX does not (at least on my Mac Mini). And 2) Channels allow the client to do the transcoding when live streaming MPEG 2 on my Apple TV’s.

For recordings the savings in disk space and the multiple playbacks would benefit if there were stored as MP4 Files.

Back to PLEX, I do use it heavily for multi-user profiles with DIRECT PLAY of all MP4 content. I mainly use it for movies but I do have some tv series.

yes it does live transcoding for playback for web interface and roku.

mp4 is a very easy container to stream, especially with aac audio. pretty much anything can play this.

I kinda forget they do do hardware transcoding with h264_vaapi so it shouldn’t be too hard to support transcoding of the recording if they wanted to.

On my nas I have had 2 SD transcoding to mp4 and 1 720p plex transcoding happening at the same time. the SD transcoding were going kinda slow, but managed. The 720p direct playback was working fine. My nas was 100% cpu during this time however.

I think when they playback on apple tv there is no transcoding. Their player in appletv supports mpeg2 directly.

resurrecting this . With today's hardware (ie good quicksync on the last 4 generations of CPUs) this is no longer the system crippler it once was.

Benefits of transcoding during recording are reduced storage space and potentially a reduced need to transcode to the client.